Weld neck pipe flanges are installed by welding the pipe to the neck of the flange. This allows for the transfer of stress from the flange to the pipe itself. This also reduces high stress concentration at the base of the hub. Weld necks are often used for high pressure applications. The inside diameter of this attachment is machined to match the inside diameter of the pipe.

The type of flange is slip on flange, weld neck flange, plate flange, threaded flange, socket weld flange, lap joint flange , slip on flange, blind flange